I used to train in Wing Chun and I have done the wall bag thing, rice, sand, gravel and iron shot. It was fun but I stopped doing that. It's already been said, but be careful w/ oldschool methods of conditioning.
Since your interested in conditioning your hands, you might be interested in simply strengthening the muscles in your hands and forearms. Combining the strength training with alignment work and you'll have a more solid strike, and be less prone to injury.
check out the book "Mastery of Hand Strength" by John Brookfield.
full of 'good ways to strengthen your hands and wrists without damaging yourself.
there used to be alot of the material in that book on the web but I can't find it, or I would have posted the links instead of the book.

"It does not matter who the master is. It does not matter what the face looks like. The masters are of the Qimen school of qigong/meditation which is related to Zen. The master wears white robes, and the predecessor master wears bright gold robes. The qimen school travels the univers and is not restricted to what paradise they live in. It has many masters" -Serious Harm

just click on the 'more' link, 34 pages. Theres enough info in that site that you won't need top buy his book like I did.
I do levers in all directions, holding a chair by the leg at a half curl for time, grippers. My favorite is putting 2 plates at the gym together w/ the smooth side facing out so theres nothing to grab, clamping onto it w/ my hand and dead lifting it. Personal best was 2 25lb plates.
Also play handball.
no reason to hurt your joints

Here's my take. Striking hard objects causes microfractures in your bones as they absorb the impact. As the microfractures heal, the bone cells 'lattice' themselves and become essentially denser. This is why older women 'powerwalk' to retain bone density and fight osteoporosis. I'm not sure that the daily training is going to help much... bones don't heal as quickly as other body components. You should definately take a healing period if you do this.

Also, your knuckles will face exterior fractures, causing the latticework to build up... causing calcium spurs that may inhibit range of motion, pinch tendons, pinch nerves, or just break off and wreak all kinds of havoc.

KenpoDude, Breaking a bone makes it more likely to break in the future. Weightlifting and powerwalking (I guess...) don't create microfractures, they compress the bones, making them denser, which is what fights osteioperosis, but hey, maybe its different in your reality.

KenpoDude, Breaking a bone makes it more likely to break in the future. Weightlifting and powerwalking (I guess...) don't create microfractures, they compress the bones, making them denser, which is what fights osteioperosis, but hey, maybe its different in your reality.

Are you seriously claiming that powerlifting makes your bones shrink?
KenpoDude is right.

Originally Posted by Stickx

It must suck for legit practitioners of tai chi like Cullion to see their art get all watered down into exercise for seniors.

Those who esteme qi have no strength. ~ Exposition of Insights into the Thirteen Postures Attrib: Wu Yuxiang founder of Wu style tai chi.

He was right about the powerwalking, note that the MD says that fractures==bad and that exercises increase bone density, not some non-sensical latticework of microfractures that'll give you arthrtus later in life and bane your bones easier to break in the future.